Girls, help me understand why she goes out of her way to say hi and then kind of ignores me next time?

[Anonymous]

There's this girl that I like. We never talked as we are not in the same team. She looks kind of introverted and does not interact much with others.
I'd say that I noticed something strange from her. Going from staring to wanting to be around me physically to looking away when passing by sometimes. Yesterday as she passed by me from behind, she kind of turns her head towards me and says hi. She did not look at me, though she turned her head, plus her hi was a bit... shy. Quiet. Anyway I realized she went out of her way to say hi. I answered back with an energetic "hi"
Today. Different story. She was walking on the corridor towards the exit. As she was approaching my desk I looked her way (when she was about 2 meters away). She wasn't looking and I'd dare to say she was avoiding making eye contact, because it would have been impossible to not notice I was looking at her. I said hi when she was right next to my desk. She didn't look or respond, but she said hi to someone from her team that passed by her at the same time.
What is she going out of her way to say hi, to her behaviour next day?

Updates

+1 y

Anyone else willing to share an opinion? Girls, come on! What's going on with her?

[Junlian]

Auum its from 2 or three things. 1) she's shy and wants to say hi to people to seem friendly. 2) she dont know how to express herself in a manner that us guys will get. 3) she's got this brainwashed mentality to not act desperate, needy. clingy, or other ridiculous acts that maje seem. a certain way and hide the truth. May be she likes you and want to hide it, maybe she likes to see you but sges huding it. Etc.

[Asker]

She does not actually say hi to people randomly. This is why it struck me when she said hi to me, though she could have simply passed by... as she does with others...

[Anonymous]

"She was walking on the corridor towards the exit. As she was approaching my desk I looked her way" - this doesen't make sense. There a corridor in the classroom? Was she standing right opposite you or not?

[Asker]

:)) English not my native, so I don't know how to explain it. Imagine a wider space for walking in the center of the room, with desks on the left and the right...
My desk is on the left of that "lane", the last row before the exit. Now... my desk is placed in such a way that I am standing with my back to the exit door. So I can see whenever someone is walking down the lane towards the exit...
If still not clear enough, doesn't matter, I appreciate your efforts though :)

[Opinion Owner]

Oh ok. Then i guess she mustve just been really shy also if u stared at her in front of others?:) shy girls dont like too much attention:)

[Anonymous]

You're putting too much thought into it. She probably didn't notice you the second time.

[Asker]

No that's kind of impossible, cause I was right there... she avoided looking my way on purpose and though I said hi she didn't respond or look...

[Ginger111]

She's probably just really really shy around you. Have you tried being flirty with her? Shy girls tend to not react to signs of flirting.